Decomposition of nitric oxide under oxygen excess condition

NO decomposition in the presence of excess oxygen and a small amount of hydrocarbons was examined on various kinds of MFI-type metallosilicates. In every case the activity was increased at the temperature range where combustion activity was increased. Among the catalysts tested, Co-silicate showed the highest performance, which had both redox and acidic properties. Pt modification to the catalyst resulted in both an increase in combustion activity and a NO decomposition activity at lower temperature, especially on Pt-ion-exchanged Co-silicate. Using these bifunctional catalysts and the control of the oxidation state of the surface during the reaction by addition of a suitable hydrocarbon provides a high performance for the NO decomposition reaction in the excess oxygen atmosphere.